Spring unit for platform rocking chair



Dec. 4, 1956 J, TUNNELL 2,772,723

SPRING UNIT FOR PLATFORM ROCKING CHAIR Filed Feb. 8, 1954 INVENTOR. JACK a TUNA/ELL ATTORNEYS United States Patent 3 Claims. (Cl. 155-71) This invention relates to platform rocking chairs, and

more particularly to an improved spring unit for con-.

necting and controlling the rocking movement of achair structure on a platform base.

As is well known, platform rocking chairs are characterized in general by a chair structure formed with a skirt having rocker surfaces resting for rocking movement on a platform base, and having the rocking movement thereof controlled by spring means which also serve to connect the chair structure on the platform base. Because the rocking movement in a chair structure of this sort is in the nature of an endlessly repeating one, and because the force of the movement varies widely and may be quite severe at times, great difliculty has previously been encountered in providing the spring means with a mounting arrangement that would give adequate and dependable protection against structural failure during a satisfactory period of use.

According to the present invention, a spring unit for platform rocking chairs is providedin which the mounting means aflords exceptional strength against the stresses that have previously caused failure'diiiiculties, and whichhas been found under actual tests to be dependable against failure far beyond the greatest use that might be expected in a chair of this sort.

The spring unit of the present invention is described in further detail below in connection with the accompanying drawings, in which:

Fig. 1 is a perspective view showing a platform rocking chair in dotted outlines with spring units embodying the present invention represented in full lines to illustrate the disposition they would have in a chair of this sort;

Fig. 2 is an enlarged side elevation of the spring unit shown in Fig. 1;

Fig. 3 is a top plan view corresponding to Fig. 2;

Fig. 4 is a left end elevation corresponding to Fig. 2; and

Fig. 5 is an enlarged sectional detail taken substantially on the line 55 in Fig. 3.

In Fig. 1 the platform rocking chair indicated is shown as comprising a chair structure C having a skirt S formed with rocker surfaces at R resting for rocking movement on a platform base P. The spring units of the present invention are indicated generally by the reference numeral 10 arranged for connecting the chair skirt S with the platform base P and for controlling the rocking movement of the chair C by reaction in opposition to rocking movement at the rocker surfaces R in either direction on the platform base P. v g

As seen in clearer detail in Fig. 2, each spring unit 10 comprises .a' pair of identical mounting brackets 12 assembled in complementary relation with a pair of coil springs 14. Each mounting bracket 12 has a mounting flange portion 16 arranged in parallel relation with respect to the axis of the springs 14, and these flange prortions 16 serve for attachment of the spring unit 10 respectively to the chair skirt S and platform base P, as will be described further presently.

spring assembly flange portion 18.

2,772,723 Patented Dec. 4, 1956 ice Each of the mounting brackets 12 also has integrally arranged at right angles to its mounting flange portion 16 a spring assembly flange portion 18 at which opposite ends of the coil springs 14 are assembled and secured in spaced relation-and in parallel alignment with the mounting flange portions 16. The spaced disposition of the coil springs 14 tends to maintain the chair structure C at rest and further causes the previously noted spring reaction in opposition to any rocking movement of the chair structure C. In this connection, it should be noted that'the spring reaction occurs by'resistance of one or the other of the springs 14 to elongation upon rocking movement of the chair structure C, and that this reaction must be transmitted through the mounting brackets 12 in'a manner that imposes severe flexure stresses at the juncture between the mounting flange and spring assembly flange portions 16 and 18 of the mounting brackets 12, which is the point at which difliculty with structural failure has previously been centered.

According to the present invention the mounting brackets 12 are formed to withstand these severe flexure stresses by arranging a plurality of reinforcing ribs 20 spaced transversely along the junction of the bracket portions 16 and 18 with each rib 20 extending at 45 with respect to the bracket portions 16 and 18 across the juncture thereof and continuing for a substantial distance in the spring assembly flange portion 18 with the outer rib edges formed parallel with respect to the plane of said The result of this arrangementof the ribs 20 is not only to strengthen the spring assemblyflange 18, but also to carry this strength across thejuncture with the mounting flange portion 16 and thereby avoid any concentration of the flexure stresses atthis juncture to cause the frequent failures that have previously been encountered. a

Inorder to arrange the mounting brackets 12 for convenient attachment to the chair skirt S and the platform base P, as previously noted, the mounting flange portion 16 of each mounting bracket 12 is formed with fastening means apertures 22 centrally thereof and adjacent each end, and it should be noted that the reinforcing ribs 20 are spaced in transverse alignment with these apertures 22, so as to strengthen the mounting brackets 12 in direct alignment with their attachment points. The attachment apertures 22 are preferablyembossed and countersunk as illustrated in the drawings, so .as to provide for secure attachment of the mounting flange portions 16 by screws or the like (not shown). Also, the end edges of the spring assembly flange portions 18 may advantageously have edge flanges 24 formed thereat and arranged to extend laterally as at 26 in substantially flush relation with the attachment faces of the mounting flange portion 16 for further strengthening and adequately securing the spring unit 10 in the chair structure.

The assembly of the springs 14 with the mounting brackets 12 is provided for by sets of positioning bosses 28 and a clamping lip30 formed in the spring assembly flange portions 18 for fixing the end coils of each spring 14 on the outer faces of the flange portions 18, with the remaining intermediate spring coils disposed between the inner faces of these flange portions 18.

The present invention has been described in detail above for purposes of illustration only and is not intended to be limited by this description or otherwise except as defined in the appended claims.

I claim:

1. A spring unit for a platform rocking chair, said unit comprising a pair of mounting brackets for attachment respectively to a rocking chair and platform base therefor, and a pair of springs assembled with said brackets for reacting in opposed relation to rocking movement of said chair on said platform base, each of said mounting brackets having a mounting flange portion and a spring assembly flange portion arranged at right angles, and each of said mounting brackets being formed with a plurality of transversely extended reinforcing ribs spaced along the juncture of said bracket portions, said ribs each extending at 45 with respect to said bracketportions' and continuing for a substantial distance in said spring assembly flange portion formed with its outer edge parallel with respect to the plane of said spring assembly flange portion.

2. A spring unit for a platform rocking chair of the type having a chair skirt formed with rocker surfaces resting for rocking movement on a platform base, said unit comprising a pair of mounting brackets assembled with a pair of springs and arranged for attachment respectively to said chair skirt and said platform base to dispose said springs spaced in parallel alignment with respect to the plane in which said rocker surfaces move on said platform base, the spaced disposition of said springs being adapted to maintain said rocker skirt at rest and causing said springs to react in opposition to rocking movement of said chair skirt in either direction on said platform base, said mounting brackets each having integral mounting flange and spring assembly flange portions arranged at right angles, said mounting flange portions each having fastenin means apertures arranged along the outer edges thereof centrally and adjacent each end thereof, and each of said mounting brackets being formed with transversely extended reinforcing ribs aligned with said apertures, extending at 45 with respect to said bracket portions across the juncture thereof, and continuing for a substantial distance in said spring assembly flange portion formed with the outer rib edges parallel with respect to the plane of said spring assembly flange portion. 7

3. A spring unit for a platform rocking chair of the type having a chair skirt formed with rocker surfaces resting for rocking movement on a platform base, said spring unit being adapted to connect said chair skirt with said platform base and control said rocking movement, and said spring unit comprising a pair of identical mounting brackets assembled in complementary relation with a pair of coil springs, said brackets each having a mount ing flange portion arranged in parallel relation to the axis of said springs for attachment respectively to said chair skirt and platform base to move in parallel rela tion to the plane in which said rocking motion occurs, and said brackets each having integrally arranged at right angles to said mounting flange portions a spring assembly flange portion at which opposite ends of said springs are assembled and secured in spaced relation and in parallel alignment with said mounting flange portions, the spaced disposition of said springs being adapted to maintain said rocker skirt at rest and to cause said springs to react in opposition to rocking movement of said chair skirt in either direction on said platform base, said mounting flange portions each having fastening means apertures formed along the outer edges thereof centrally and adjacent each end thereof, and each of said mounting brackets being formed with transversely extending reinforcing ribs aligned with said apertures, said ribs extending at 45 With respect to said bracket portions across the juncture thereof and continuing for a substantial distance in said spring assembly flange portion formed with the outer rib edges parallel with respect to the plane of said spring assembly flange portion.

References Cited in the file of this patent UNITED STATES PATENTS 448,240 Kade Mar. 17, 1891 1,611,708 Amsden Dec. 21, 1926 2,244,614 Fox June 3, 1941 

